Android：FragmentManager在新的Fragment膨胀时返回空白片段布局 - 根本不调用onCreateView（）方法

Question

我的片段不会在帧布局中膨胀。请帮助我的代码：

我的MainActivity扩展了AppCompatActivity，而不是FragmentActivity，因为我需要使用actionbar。

  public void showFragmentWomen(String title) {
        showFragment(FragmentWomen.newInstance(title), false);
    }

    private void showFragment(Fragment fragment, boolean allowStateLoss) {
        FragmentManager fm = mFragmentManager;

        FragmentTransaction ft = fm.beginTransaction().replace(R.id.container, fragment);

        ft.addToBackStack(null);

        if (allowStateLoss || !BuildConfig.DEBUG) {
            ft.commitAllowingStateLoss();
        } else {
            ft.commit();
        }

        fm.executePendingTransactions();
    }

片段代码：

import android.graphics.PorterDuff;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.content.ContextCompat;
import android.support.v4.content.res.ResourcesCompat;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ImageView;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;

import com.android.msahakyan.angesbags.R;

/**
 * A simple {@link Fragment} subclass.
 * Use the {@link FragmentWomen#newInstance} factory method to
 * create an instance of this fragment.
 */
public class FragmentWomen extends Fragment {

    private static final String KEY_MOVIE_TITLE = "key_title";
    private Spinner spinner1;
    public FragmentWomen() {
        // Required empty public constructor
    }

    /**
     * Use this factory method to create a new instance of
     * this fragment.
     *
     * @return A new instance of fragment FragmentWomen.
     */
    public static FragmentWomen newInstance(String movieTitle) {
        FragmentWomen fragmentWomen = new FragmentWomen();

        return fragmentWomen;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_women, container, false);
    }

    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        spinner1 = (Spinner) view.findViewById(R.id.frag_women_spinner);
        spinner1.setOnItemSelectedListener(new CustomOnItemSelectedListener());
    }
    public class CustomOnItemSelectedListener implements AdapterView.OnItemSelectedListener {

        String firstItem = String.valueOf(spinner1.getSelectedItem());

        public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
            if (firstItem.equals(String.valueOf(spinner1.getSelectedItem()))) {
                // ToDo when first item is selected
            } else {
                Toast.makeText(parent.getContext(),
                        "You have selected : " + parent.getItemAtPosition(pos).toString(),
                        Toast.LENGTH_LONG).show();
            }
        }

        @Override
        public void onNothingSelected(AdapterView<?> arg) {

        }

    }
}